(1) Field of the Invention
The present invention relates to substrate treating methods and apparatus for performing a predetermined treatment of substrates such as semiconductor wafers by supplying a treating solution such as a developer, resist solution or rinse solution in a generally strip form to a surface of each substrate.
(2) Description of the Related Art
In a semiconductor device manufacturing process, for example, a slit scan developing mode has been in wide use in recent years as one of the methods for developing photoresist film formed on the surface of a semiconductor wafer. In this developing mode, as disclosed in Japanese Patent Publication (Unexamined) No. 1999-221511, for example, while a developer delivery nozzle having a discharge opening in slit form in a lower surface thereof is moved horizontally and linearly from one end to the other end of a wafer held still and in horizontal posture by a wafer holder, a developer is delivered from the discharge opening of the delivery nozzle to the surface of the wafer to form a puddle of the developer thereon. By forming a puddle of the developer on the wafer held still in this way, a resulting resist film pattern has a greatly improved line width uniformity.
However, while a planar area in which the developer delivery nozzle moves is rectangular, a developing cup surrounding the semiconductor wafer and adjacent areas has a circular circumference. As a result, part of the developer delivered from the slit-shaped discharge opening of the developer delivery nozzle falls outwardly of the wafer surface to be drained and abandoned without forming the puddle. This constitutes a problem of wasteful consumption of the developer.